The object of this research program is to investigate the neural processing mechanisms in the visual cortex that provide the basic information leading to the perception of the position and movement of objects in three-dimensional space. These studies are conducted by exploring in alert, visually active monkeys the response properties of cortical neurons to stereoscopically viewed patterns. During the coming year we propose: (1) To complete a study of the response of neurons in cortical areas 17 and 18 to dynamic random-dot stereograms. (2) To extend our investigation of the cortical representation of motion-in-depth to the prestriate cortex and possibly to subcortical structures, the pulvinar in particular. (3) To study in some detail the binocular eye movements of the monkey performing a depth discrimination task, and their relations to the associated neuronal activity in visual cortex.